Add documentation for Runtime_events events

[sadiqj]

Should be of interest to at least @kayceesrk and @tmcgilchrist

We could probably flesh these out further over time.

[tmcgilchrist]

This is a good improvement to the documentation, thank you. 👍🏻

Minor question, there is no corresponding event for caml_adjust_minor_gc_speed. Does it make sense to have one for that? It seemed out of place when caml_adjust_gc_speed emits an event and this one doesn't.

ocaml/runtime/memory.c

Lines 281 to 285 in 8bbb374

	/* This function is analogous to [caml_adjust_gc_speed]. When the
	accumulated sum of [res/max] values reaches 1, a minor GC is
	triggered.
	*/
	CAMLexport void caml_adjust_minor_gc_speed (mlsize_t res, mlsize_t max)

[kayceesrk]

This is much appreciated. Thank you.

[sadiqj]

Minor question, there is no corresponding event for caml_adjust_minor_gc_speed. Does it make sense to have one for that? It seemed out of place when caml_adjust_gc_speed emits an event and this one doesn't.

Yes, I think this would be a good idea.

[kayceesrk]

I'd be happy to merge once https://github.com/ocaml/ocaml/pull/13382/files#r1722740060 is resolved.

[kayceesrk]

The CHANGES entry also needs to be updated.

[kayceesrk]

I've updated the Changes file and squashed the commits at @sadiqj's request.